问题
选择题
“thanks” is polite when someone has done you a favour, but saying it too often is quite another thing.
A．Though saying
B．If saying
C．Saying
D．In spite of saying
答案
答案：C
题目分析：句意：当别人帮你忙的时候，说“谢谢”是礼貌的，但是说的太频繁又是另外一件事。这里第一个is是谓语，前面的是主语，用动名词做主语，所以选C。